Disease-related weight loss is relatively common in patients with newly diagnosed multiple myeloma (MM), but limited data exist regarding the effects of nutritional status on survival. The aim of this study was to assess the relationship between malnutrition (as measured by Patient-Generated Subjective Global Assessment [PG-SGA]) and clinical characteristics of patients with MM, and to investigate the association between the PG-SGA score before chemotherapy and overall survival in MM patients.Using the PG-SGA score, we retrospectively explored the effect of malnutrition on the survival of Asian patients with MM.We divided 216 patients with MM into three groups based on their PG-SGA scores. Of these patients 23% (n = 50) had PG-SGA scores ≥9, indicating severe malnutrition requiring specialist nutrition intervention. Body mass index and serum hemoglobin were independently associated with PG-SGA scores (P < 0.05). The median survival time was not reached in nourished patients with PG-SGA scores of 0 to 3, 58.7 mo in moderately malnourished patients with PG-SGA scores of 4 to 8, and 35 mo in severely malnourished patients with PG-SGA scores ≥9 (P = 0.001). Multivariate analysis revealed that PG-SGA scores ≥9 compared with PG-SGA scores of 0 to 3 (hazard ratio [HR], 2.347; 95% confidence interval [CI], 1.271-4.334; P = 0.006), International Staging System (ISS) stage III compared with ISS stage I (HR, 2.360; 95% CI, 1.271-4.379; P = 0.007), and autologous stem cell transplantation (HR, 0.388; 95% CI, 0.248-0.606; P < 0.001) were associated with overall survival.A higher PG-SGA score before chemotherapy was associated with reduced survival among patients with MM. Nutritional evaluation should be an integral part of the clinical assessment of MM patients, and the PG-SGA score would be an appropriate tool to evaluate nutritional status.